Facile fabrication of organic/inorganic nanotube heterojunction arrays for enhanced photoelectrochemical water splitting

Abstract

Organic/inorganic heterojunction photoanodes are appealing for making concurrent use of the highly photoactive organic semiconductors, and the efficient dielectric screening provided by their inorganic counterparts. In the present work, organic/inorganic nanotube heterojunction arrays composed of TiO2 nanotube arrays and a semiconducting N,N-(dicyclohexyl) perylene-3,4,9,10-tetracarboxylic diimide (PDi) layer were fabricated for photoelectrochemical water splitting. In this arrayed architecture, a PDi layer with a tunable thickness was coated on anodic TiO2 nanotube arrays by physical vapor deposition, which is advantageous for the formation of a uniform layer and an adequate interface contact between PDi and TiO2. The obtained PDi/TiO2 junction exhibited broadened visible light absorption, and an effective interface for enhanced photogenerated electron-hole separation, which is supported by the reduced charge transfer resistance and prolonged excitation lifetime via impedance spectroscopy analysis and fluorescence emission decay investigations. Consequently, such a heterojunction photoanode was photoresponsive to a wide visible light region of 400-600 nm, and thus demonstrated a highly enhanced photocurrent density at 1.23 V vs. a reversible hydrogen electrode. Additionally, the durability of such a photoanode can be guaranteed after long-time illumination because of the geometrical restraint imposed by the PDi aggregates. These results pave the way to discover new organic/inorganic assemblies for high-performance photoelectric applications and device integration.

Low Detection Limit Circularly Polarized Light Detection Realized by Constructing Chiral Perovskite/Si Heterostructures

“…The longer carrier lifetime of the perovskite/Si heterostructure will potentially benefit the photoresponse of the optoelectronic device, leading to outstanding photodetection performance. [ 47–49 ] Based on the above results, we conclude that the (R‐MPA) 2 MAPb 2 I 7 /Si heterostructure has been successfully constructed with high crystalline quality and reliable interfacial connection.…”

Structure/Property Control in Photocatalytic Organic Semiconductor Nanocrystals

“…For instance, we uniformly coated a CH‐PTCDI overlayer on the anodized TiO 2 NTs by PVD, yielding n/n organic/inorganic heterojunction arrays for water splitting. [ 74 ] By controlling the source‐substrate distance, the thickness of the CH‐PTCDI overlayer could be tuned from approximately zero to ten nm (Figure 11f–j). The tunable interface structure gave rise to different optical and electronic properties.…”

Perylene diimide self-assembly: From electronic structural modulation to photocatalytic applications

“…Chen and coworkers succeeded in achieving the photocatalytic hydrogen production performance via constructing a C 3 N 4 /PDI composite catalyst for the enhanced performance, mainly because the photogenerated holes in C 3 N 4 are assumed to rapidly transfer to the PDI moelcules, which effectively prevented the recombination of photogenerated electrons and holes in C 3 N 4 [87] . Sun et al fabricated a PDI/ Zn 0.5 Cd 0.5 S composite with PDI as an electron collector for the inhibition of photogenerated charge recombination [226] . All these studies regarded PDI as a kind of auxiliary catalyst but not host photocatalysts.…”